On Oct 13, 2014, Mike Laidlaw & Cameron Lee showed off the motherload. PC UI along with all new gameplay-- even some never before seen cinematics including Cassandra, Leliana, Josephine, & Cullen. They give you a peek at the war table, agent interaction, choices, new area and more. If you see no other gameplay, see this one. This gameplay video shows off the Mouse & Keyboard UI.

Warning - Light spoilers: It appears to show the scene where you meet your advisors for the first time and the conversation afterward.

Advisor conversations
Knight Enchanter game play
Resurgence (the heal) is one of the Knight Enchanter spells and takes Focus
Spirit Blade can deflect dragon breath
50% health recovery on easy, 25% on normal, 10% on hard
Crafting items do not take up inventory space
Lots of graphics options
Friendly fire toggle
Mages can wear coats and pants
No XP for killing harmless wildlife; kill enough of one type of animal/monster for "research" and you can upgrade your damage against them
You can't get crafting materials from destroying items in single-player, but you can in multiplayer
Mounts are not kill-able
Politics
"I am no herald"
You can disavow the Chantry if you're Dalish